[Utility of procalcitonin, C-reactive protein and leukocyte count in the detection of meningococcal disease during an epidemic cluster]. / Utilidad de la procalcitonina, proteína C reactiva y recuento leucocitario en la detección de enfermedad meningocócica durante un brote epidémico.

OBJECTIVE: To determine the clinical utility of biological markers of the acute phase of bacterial infection (procalcitonin, C-reactive protein and leukocyte count) in invasive meningococcal disease during an epidemic cluster. PATIENTS AND METHODS: Thirty-six patients with feverish syndrome who visited the emergency unit of our hospital within a 6-month period were studied. In all patients, serum procalcitonin and C reactive protein levels and leukocyte count were determined, and blood culture was performed. RESULTS: Invasive meningococcal disease, confirmed by blood culture, was found in seven of the 36 patients studied. The most frequent clinical presentation was a feverish syndrome of less than 24 hours of onset, progressing to sepsis in subsequent hours. Comparison of procalcitonin and C reactive protein concentrations in patients with and without meningococcal disease revealed that procalcitonin and C reactive protein levels greater than 10 ng/ml and 49.95 ng/ml respectively had high sensitivity, specificity and predictive values. Procalcitonin levels < 0.5 ng/ml were useful to easily rule out invasive meningococcal disease. In the case of leukocyte count, no value with clinical significance could be established, although counts were higher in patients with invasive meningococcal disease. CONCLUSIONS: The finding of prolactin levels of < 0.5 ng/ml and/or C-reactive protein levels of < 49.95 ng/ml in children or teenagers with fever of less than 24 hours of onset indicates a low probability of invasive meningococcal disease in epidemic situations.